Updated · Tires
The donut, or temporary spare
A compact spare is narrower and lighter than your regular tire, often on a small steel wheel. It saves trunk space and weight. Its sidewall or a label on the wheel says it's for temporary use and gives a top speed, usually 50 mph.
Most need much more air than a regular tire, often 60 psi; the right number is printed on the tire or the door-jamb sticker. A donut that has sat for years in a hot trunk is often low when you finally need it.
The full-size spare
A full-size spare is the same size as your road tires. A matching spare sits on the same kind of wheel and can even join the tire rotation. A non-matching one is the right size but may ride on a plain steel wheel or have a different tread.
Pickups, many SUVs and minivans carry it under the rear, lowered by a cable. Those cables can rust or seize, so lower the spare at home once in a while to make sure it works.
No spare at all
Many newer cars skip the spare and carry a tire inflator with a bottle of sealant, or ride on run-flat tires. Sealant can get a small tread puncture to a repair, but it won't work on sidewall damage or big holes.
If you used sealant, tell the technician before the repair. It has to be cleaned out of the tire, and it can foul the pressure sensor.
Check yours before you need it
Five minutes in the driveway now beats finding a problem on the roadside later:
- Find out which kind you have and where it's stored
- Check its pressure when you check the other four
- Make sure the jack, the lug wrench and the wheel-lock key are there
- Read the date code; an old spare can be cracked even if it has never touched the road
All-wheel drive, and when to call
On some all-wheel-drive vehicles, running a tire of a different size or tread depth for long can strain the drivetrain. That's one more reason a donut should come off soon. Some owner's manuals also say which axle the temporary spare should go on.
If you get a flat, get to a safe spot away from traffic first. Then we can come mount your spare, and if there's no spare or it's flat too, we can repair the puncture or bring a replacement tire.